More flattering than 白发 (báifà, 'white hair'). 银发 emphasizes the metallic shine and is often used in marketing - 银发族 (yínfàzú, 'the silver-haired set') and 银发经济 ('silver economy') target the elderly consumer market without sounding ageist.
mistakes
发 here is fà (4th tone, 'hair' - traditional 髮), NOT fā (1st tone, 'to send' - traditional 發). The tone changes the meaning completely.
